1. Field of the Invention
The present invention relates to a bicycle hub, and more particularly to a ratchet cylinder for a bicycle hub.
2. Description of the Prior Art
A conventional bicycle hub normally consists of hub shell formed with teeth, a ratchet cylinder, an axle and a plurality of bearings. The axle is inserted in the hub shell, the ratchet cylinder is formed around its periphery with a plurality of ratchet teeth for engaging with the teeth of the hub shell in a unidirectional manner, and the bearings are disposed between the axle and the respective components.
The ratchet teeth of the ratchet cylinder are retained by a relatively rigid C-ring. When in rotation, the hub shell drives the ratchet cylinder through the engagement of the teeth and the ratchet teeth, and when in a reverse rotation, the teeth press down the ratchet teeth to make the ratchet cylinder idle. If the ratchet cylinder is only provided with three ratchet teeth, which won't affect the C-ring since the distance between the ratchet teeth is relatively large. However, when there are six ratchet teeth on the ratchet cylinder, the effect of the C-ring for retaining the ratchet teeth will be adversely affected due to the ratchet teeth are disposed at a relatively short distance from one another, causing misalignment of the ratchet teeth.
Hence, the C-ring is replaced with a circular elastic clasp, the elasticity of the elastic clasp can overcome the bad retaining effect of the rigid C-ring, however, the circular elastic clasp is difficult to produce. Moreover, the elastic clasp has elastic fatigue problem.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.